The present invention generally relates to a connection apparatus of a circuit board, which is applicable to, for instance, a connection of an extendible internal memory employed in a personal computer. More specifically, the present invention is directed to a connection apparatus of a circuit board, having high operability and high reliability.
Very recently, personal computers have been considerably, widely utilized in various fields. The process contents of these personal computers depend upon various needs of users, and thus the systems have been established such that the internal memory may be extended in response to user requests.
For instance, in case of a notebook type personal computer as illustrated in FIG. 11 and FIG. 12, a concave 103 used to mount an extendible internal memory 102 is provided on the lower surface of a personal computer body 100 when a lid 101 is opened, so that the extendible internal memory 102 which is necessary to execute manage data process can be substituted.
FIG. 13 is a bottom view of the conventional extendible internal memory 102. As shown in FIG. 13, female connectors 105a and 105b are provided on both sides of a printed board 104 in parallel to each other, and a plurality of IC memory chips 106 are arranged between the connectors 105a and 105b.
A large number of terminal pins 107 are fixed on the connectors 105a and 105b in order to be connected to a printed board (not shown) of the personal computer body 100. For example, when the total number of terminal pins 107 is 50, the terminal pins 107 numbered from 1 to 25 are fixed to the left-sided connector 105a (as viewed in FIG. 13), are also the terminal pins 107 numbered from 26 to 50 are fixed to the right-sided connector 105b, so that these terminal pins 107 are connected to the IC memory chips 106.
To define the mounting direction of the extendible internal memory 102 with respect to the personal computer body 100, a notch portion 108 is formed at one corner of the printed board 104, and furthermore another notch portion is formed on the above-described concave 103 of the personal computer body 100 in correspondence with this notch portion 108.
While this extendible internal memory 102 is overlapped on the printed board employed in the personal computer body 100, the female connectors 105a and 105b provided on the extendible internal memory 102 are fitted to the male connectors of the personal computer body 100, so that this extendible internal memory 102 is electrically connected to the personal computer body 100. As a result, the memories are extendably provided.
However, if the above-described conventional extendible internal memory 102 would be inserted into the personal computer body 100 along the incorrect insertion direction, then the connectors 105a and 105b would be mechanically destroyed. As a result, there are many possibilities that the memories could not be extendably provided.
Since there is a risk that the electric circuits employed in the personal computer body 100 are electrically destroyed (mainly shortcircuited) when the extendible internal memory 102 would be inserted into the personal computer body 100 along the incorrect direction, a protection circuit for preventing such a shortcircuit is required.